Fiber collecting media strip for a mist eliminator

Abstract

A fiber bed mist eliminator has a fiber bed which is formed of a composite fiber bed collecting media strip including a collection layer which is not subjected to needle punching. The fiber bed can be made very thin while retaining high efficiency in removing small particles of aerosol from a gas stream passing through the fiber bed. The fiber bed collecting media strip lends itself to be applied to the mist eliminator by spirally wrapping the element onto the mist eliminator. The fiber bed collecting media strip can overlap itself to seal at the locations where the fiber element overlaps itself. The fiber bed collecting media strip can be provided to the field in different formats for use in making a mist eliminator fiber bed.

1. A fiber bed assembly for a fiber bed mist eliminator used to remove aerosols and/or wetted soluble solids from a moving gas stream, the fiber bed assembly comprising:
 a fiber bed support having a wall defining an upstream space and a downstream space, the wall including openings therein to permit the gas stream to move generally freely through the wall from the upstream space to the downstream space; 
 a fiber bed supported by the fiber bed support and generally covering the wall openings so that the gas stream passes through the fiber bed moving from the upstream space to the downstream space, the fiber bed comprising a composite fiber bed collecting media strip including;
 an outer layer comprising a mat of fibers constructed to provide structural integrity to the composite fiber bed collecting media strip, 
 an inner layer comprising a mat of fibers constructed to provide structural integrity to the composite fiber bed collecting media strip, and 
 an intermediate layer formed to have a higher collection efficiency than the inner and the outer layers, the intermediate layer being sandwiched between the outer and inner layers, the intermediate layer being non-needle punched, 
 the outer layer and inner layer each comprising fibers having an average diameter of about 6 microns or more and the intermediate layer comprises fibers having an average diameter of about 5 microns or less, the fibers of the outer layer, inner layer and intermediate layer being made of glass, and the fibers of the inner and outer layers being needle punched. 
 
 
     
     
       2. A fiber bed assembly as set forth in  claim 1  wherein the outer layer, inner layer and intermediate layer are free of any fixed interconnection with each other. 
     
     
       3. A fiber bed assembly as set forth in  claim 1  wherein the composite fiber bed collecting media strip has a width less than a height of the fiber bed support wall, the composite fiber bed collecting media strip being wrapped in multiple turns around the fiber bed support, at least some of the turns extending along a spiral path. 
     
     
       4. A fiber bed assembly as set forth in  claim 3  wherein at least some of the turns of the composite fiber bed collecting media strip overlap adjacent ones of the turns. 
     
     
       5. A fiber bed assembly as set forth in  claim 4  wherein the adjacent turns of the composite fiber bed collecting media strip are overlapped so as to form a drainage overhang at the location where the adjacent turns overlap thereby permitting a lower edge of the turn of the composite fiber bed collecting media strip to drain liquid from the turn. 
     
     
       6. A fiber bed assembly as set forth in  claim 5  further comprising a layer of drainage material disposed between adjacent turns of the composite fiber bed collecting media strip and projecting generally below the overhang. 
     
     
       7. A fiber bed assembly as set forth in  claim 6  further comprising a master layer of drainage material located in generally opposed relation with portions of the drainage layer projecting from between adjacent turns of the composite fiber bed collecting media strip for receiving captured liquid and soluble solids to be drained from the drainage layer between the adjacent turns. 
     
     
       8. A fiber bed assembly as set forth in  claim 4  wherein the overlap of adjacent turns of the fiber bed collecting media strip is sufficient to inhibit gas bypassing the fiber bed at the location of the overlap. 
     
     
       9. A fiber bed assembly as set forth in  claim 8  wherein the overlapping adjacent turns of the fiber bed collecting media strip have an overlap of between about two inches (5 cm) and about six inches (15 cm). 
     
     
       10. A fiber bed assembly as set forth in  claim 8  wherein the overlapping adjacent turns of the fiber bed collecting media strip have an overlap of between about two inches (5.1 cm) and about three inches (8 cm). 
     
     
       11. A fiber bed assembly as set forth in  claim 4  wherein the outer layer has indicia thereon for use in aligning a longitudinal edge of the composite fiber bed collecting media strip of one turn of the composite fiber bed collecting media strip with the preceding turn of the composite fiber bed collecting media strip. 
     
     
       12. A fiber bed assembly as set forth in  claim 4  wherein the fiber bed collecting media strip constitutes a first fiber bed collecting media strip, the fiber bed further comprising a second fiber bed collecting media strip overlying the first fiber bed collecting media strip. 
     
     
       13. A fiber bed assembly as set forth in  claim 12  wherein the first and second fiber bed media strips have longitudinal edges generally in registration with each other. 
     
     
       14. A fiber bed assembly as set forth in  claim 1  wherein the compressed thickness of the composite fiber bed collecting media strip is less than or equal to about 0.6 inches (1.5 cm). 
     
     
       15. A fiber bed assembly as set forth in  claim 1  wherein the fibers of the intermediate layer have an average diameter of about 4 microns or less. 
     
     
       16. A fiber bed assembly as set forth in  claim 1  wherein the fiber bed further comprises a drainage layer. 
     
     
       17. A fiber bed assembly as set forth in  claim 16  wherein the drainage layer is sandwiched between the inner layer and the outer layer. 
     
     
       18. A fiber bed assembly as set forth in  claim 17  wherein the fibers of the outer layer, inner layer and intermediate layer are more resistant to wetting by the aerosol in the gas stream than fibers of the drainage layer. 
     
     
       19. A fiber bed assembly for a fiber bed mist eliminator used to remove aerosols and/or wetted soluble solids from a moving gas stream, the fiber bed assembly comprising:
 a fiber bed support having a wall defining an upstream space and a downstream space, the wall including openings therein to permit the gas stream to move generally freely through the wall from the upstream space to the downstream space; 
 a fiber bed supported by the fiber bed support and generally covering the wall openings so that the gas stream passes through the fiber bed moving from the upstream space to the downstream space, the fiber bed comprising a composite fiber bed collecting media strip including; 
 an outer layer comprising a mat of fibers constructed to provide structural 
 integrity to the composite fiber bed collecting media strip, 
 an inner layer comprising a mat of fibers constructed to provide structural 
 integrity to the composite fiber bed collecting media strip, and 
 an intermediate layer sandwiched between the outer and inner layers, the intermediate layer being non-needle punched; 
 wherein the outer and inner layers are joined together at least at one of their longitudinal edge margins of the outer and inner layers. 
 
     
     
       20. A fiber bed assembly as set forth in  claim 19  wherein the longitudinal edge margins of the outer and inner layers are joined together by at least one of: sewing, stapling, heat fusing and gluing. 
     
     
       21. A fiber bed assembly as set forth in  claim 1  wherein the intermediate layer is a meltblown fiber batting. 
     
     
       22. A fiber bed assembly as set forth in  claim 1  wherein fibers of the intermediate layer are free of chemical bonding with each other. 
     
     
       23. A fiber bed assembly as set forth in  claim 22  wherein the fiber bed collecting media strip is pleated. 
     
     
       24. A fiber bed assembly for a fiber bed mist eliminator used to remove aerosols and/or wetted soluble solids from a moving gas stream, the fiber bed assembly comprising:
 a fiber bed support having a wall defining an upstream space and a downstream space, the wall including openings therein to permit the gas stream to move generally freely through the wall from the upstream space to the downstream space, the fiber bed support wall comprising an inner screen and an outer screen arranged in generally opposed relation, the fiber bed being disposed between the inner and outer screens, each screen comprising a mesh including horizontal wires and vertical wires crossing over and being interconnected with each other, the screens being arranged so that the horizontal wires of the inner screen are vertically offset from the horizontal wires of the outer screen; 
 a fiber bed supported by the fiber bed support and generally covering the wall openings so that the gas stream passes through the fiber bed moving from the upstream space to the downstream space, the fiber bed comprising a composite fiber bed collecting media strip including;
 an outer layer comprising a mat of fibers constructed to provide structural integrity to the composite fiber bed collecting media strip, 
 an inner layer comprising a mat of fibers constructed to provide structural integrity to the composite fiber bed collecting media strip, and 
 an intermediate layer formed to have a higher collection efficiency than the inner and the outer layers, the intermediate layer being sandwiched between the outer and inner layers, the intermediate layer being non-needle punched. 
 
 
     
     
       25. A fiber bed collecting media strip for forming a fiber bed of a mist eliminator used to remove aerosols and/or wetted soluble solids from a moving gas stream, the fiber bed being adapted to generally cover a support structure of the mist eliminator for generally blocking flow of the gas stream through the support structure except for through the fiber bed, the fiber bed collecting media strip comprising:
 an outer layer comprising a mat of fibers constructed to provide structural integrity to the composite fiber bed collecting media strip; 
 an inner layer comprising a mat of fibers constructed to provide structural integrity to the composite fiber bed collecting media strip; and 
 an intermediate layer sandwiched between the outer and inner layers, the intermediate layer being non-needle punched; 
 wherein the outer and inner layers are joined together along at least one longitudinal edge margin of the outer and inner layers by at least one of: sewing, stapling, heat fusing and gluing. 
 
     
     
       26. A fiber bed collecting media strip as set forth in  claim 25  wherein the intermediate layer is joined to the outer and inner layers along said one longitudinal edge margin. 
     
     
       27. A fiber bed collecting media strip as set forth in  claim 25  wherein the outer and inner layers are joined together along both longitudinal edge margins of the outer and inner layers. 
     
     
       28. A fiber bed collecting media strip as set forth in  claim 25  wherein the uncompressed thickness of the composite fiber bed collecting media strip is less than or equal to about 1.2 inches (3 cm). 
     
     
       29. A fiber bed collecting media strip as set forth in  claim 25  wherein the outer layer and inner layer each comprise fibers having an average diameter of about 6 microns or more and the intermediate layer comprises fibers having an average diameter of about 5 microns or less. 
     
     
       30. A fiber bed collecting media strip as set forth in  claim 29  wherein the fibers of the intermediate layer have an average diameter of about 4 microns or less. 
     
     
       31. A fiber bed collecting media strip for forming a fiber bed of a mist eliminator used to remove aerosols and/or wetted soluble solids from a moving gas stream, the fiber bed being adapted to generally cover a support structure of the mist eliminator for generally blocking flow of the gas stream through the support structure except for through the fiber bed, the fiber bed collecting media strip comprising:
 an outer layer comprising a mat of fibers constructed to provide structural integrity to the composite fiber bed collecting media strip; 
 an inner layer comprising a mat of fibers constructed to provide structural integrity to the composite fiber bed collecting media strip; and 
 an intermediate layer sandwiched between the outer and inner layers, the intermediate layer being non-needle punched; 
 the outer layer and inner layer each comprising fibers having an average diameter of about 6 microns or more and the intermediate layer comprising fibers having an average diameter of about 5 microns or less 
 the fibers of the outer layer, inner layer and intermediate layer being made of glass, and the outer and inner layers being needle punched. 
 
     
     
       32. A fiber bed collecting media strip for forming a fiber bed of a mist eliminator used to remove aerosols and/or wetted soluble solids from a moving gas stream, the fiber bed being adapted to generally cover a support structure of the mist eliminator for generally blocking flow of the gas stream through the support structure except for through the fiber bed, the fiber bed collecting media strip comprising:
 an outer layer comprising a mat of fibers constructed to provide structural integrity to the composite fiber bed collecting media strip; 
 an inner layer comprising a mat of fibers constructed to provide structural integrity to the composite fiber bed collecting media strip; 
 an intermediate layer sandwiched between the outer and inner layers, the intermediate layer being non-needle punched; and 
 a drainage layer sandwiched between the inner layer and the outer layer within the composite fiber bed collecting media strip. 
 
     
     
       33. A fiber bed collecting media strip as set forth in  claim 32  wherein the fibers of the outer layer, inner layer and intermediate layer are treated so as to make them resistant to wetting by the aerosol in the gas stream and fibers of the drainage layer are free of any treatment to make them resistant to wetting by the aerosol. 
     
     
       34. A fiber bed collecting media strip as set forth in  claim 25  wherein the outer layer has indicia thereon for use in aligning a longitudinal edge of the composite fiber bed collecting media strip of one turn of the composite fiber bed collecting media strip with a preceding turn of the composite fiber bed collecting media strip when the composite fiber bed collecting media strip is wrapped around the support structure of the mist eliminator. 
     
     
       35. A fiber bed collecting media strip as set forth in  claim 25  where in the fiber bed collecting media strip is in a roll. 
     
     
       36. A fiber bed collecting media strip as set forth in  claim 25  wherein the intermediate layer comprises fibers having an average diameter of about 3 microns or less interspersed in fibers having a greater average diameter. 
     
     
       37. A fiber bed collecting media strip as set forth in  claim 36  wherein the interspersed fibers have an average diameter falling in the range of about 0.01 microns to about 3 microns. 
     
     
       38. A composite fiber bed collecting media strip for use in making a fiber bed for a fiber bed mist eliminator used to remove aerosols and/or wetted soluble solids from a moving gas stream, the fiber bed being adapted to generally cover a support structure of the fiber bed assembly for generally blocking flow of the gas stream through the support structure except for through the fiber bed, the composite fiber bed collecting media strip comprising:
 an outer layer of fibers constructed to provide structural integrity to the composite fiber bed collecting media strip; 
 an inner layer of fibers constructed to provide structural integrity to the composite fiber bed collecting media strip; and 
 an intermediate layer sandwiched between the outer and inner layers, the intermediate layer being more efficient in the removal of aerosols from the gas stream than the outer and inner layers; 
 at least the outer and inner layers being formed to separate into strips including an outer layer section, and inner layer section and an intermediate layer section, 
 the inner and outer layers each having frangible portions in generally overlying relation, the frangible portions being breakable to separate the inner and outer layers into the strips. 
 
     
     
       39. A composite fiber bed collecting media strip as set forth in  claim 38  wherein the outer and inner layers are joined together at locations along at least one side of the aligned frangible portions. 
     
     
       40. A composite fiber bed collecting media strip as set forth in  claim 39  wherein the outer and inner layers are joined together at the locations by at least one of: sewing, stapling, heat fusing and gluing. 
     
     
       41. A composite fiber bed collecting media strip as set forth in  claim 38  wherein the frangible portion of each of the outer and inner layer comprises a line of perforations. 
     
     
       42. A composite fiber bed collecting media strip as set forth in  claim 38  wherein the composite fiber bed collecting media strip is in a roll. 
     
     
       43. A composite fiber bed collecting media strip as set forth in  claim 38  wherein the uncompressed thickness of the composite fiber bed collecting media strip is less than or equal to about 1.2 inches (3 cm). 
     
     
       44. A composite fiber bed collecting media strip as set forth in  claim 38  wherein the outer layer and inner layer each comprise fibers having an average diameter of about 6 microns or more and the intermediate layer comprises fibers having an average diameter of about 5 microns or less. 
     
     
       45. A composite fiber bed collecting media strip as set forth in  claim 44  wherein the fibers of the intermediate layer have an average diameter of about 4 microns or less. 
     
     
       46. A composite fiber bed collecting media strip as set forth in  claim 44  wherein the fibers of the outer layer, inner layer and intermediate layer are made of glass. 
     
     
       47. A composite fiber bed collecting media strip as set forth in  claim 38  further comprising a drainage layer sandwiched between the inner layer and the outer layer. 
     
     
       48. A composite fiber bed collecting media strip as set forth in  claim 38  wherein the outer layer has indicia thereon for use in aligning a longitudinal edge of the composite fiber bed collecting media strip of one turn of the fiber bed collecting media strip with the preceding turn of the composite fiber bed collecting media strip when the composite fiber bed collecting media strip is wrapped around the support structure of the fiber bed mist eliminator. 
     
     
       49. A fiber bed assembly for a fiber bed mist eliminator used to remove aerosols and/or wetted soluble solids from a moving gas stream, the fiber bed assembly comprising:
 a fiber bed support having a wall defining an upstream space and a downstream space, the wall including openings therein to permit the gas stream to move generally freely through the wall from the upstream space to the downstream space;
 a fiber bed supported by the fiber bed support and generally covering the wall openings so that the gas stream passes through the fiber bed moving from the upstream space to the downstream space, the fiber bed comprising an elongate fiber bed collecting media strip wrapped around the fiber bed support in multiple turns, at least some of the turns extending along a spiral path, the fiber bed collecting media strip being generally flat and at least some of the turns overlapping adjacent turns, the fiber bed further comprises sealing material disposed over the fiber bed collecting media strip at locations where turns of the fiber bed collecting media strip overlap each other for sealing between overlapping turns, the sealing material permitting flow of gas therethrough. 
 
 
     
     
       50. A fiber bed assembly as set forth in  claim 49  wherein the sealing material comprises a generally cylindrical roving wound on the fiber bed support. 
     
     
       51. A fiber bed assembly as set forth in  claim 50  wherein the roving is located only where the turns of the flat fiber bed collecting media strip overlap. 
     
     
       52. A fiber bed assembly for a fiber bed mist eliminator used to remove aerosols and/or wetted soluble solids from a moving gas stream, the fiber bed assembly comprising:
 a fiber bed support having a wall defining an upstream space and a downstream space, the wall including openings therein to permit the gas stream to move generally freely through the wall from the upstream space to the downstream space; 
 a fiber bed supported by the fiber bed support and generally covering the wall openings so that the gas stream passes through the fiber bed moving from the upstream space to the downstream space, the fiber bed comprising an elongate fiber bed collecting media strip wrapped around the fiber bed support, at least some of the turns extending along a spiral path, at least some of the turns overlapping adjacent turns, and an intermediate drainage layer located between adjacent turns of the fiber bed collecting media strip. 
 
     
     
       53. A fiber bed assembly as set forth in  claim 52  wherein the intermediate drainage layer includes a portion projecting outward from between adjacent, overlapping turns of the fiber bed collecting media strip. 
     
     
       54. A fiber bed assembly as set forth in  claim 53  wherein the adjacent turns of the fiber bed collecting media strip are overlapped so as to form a drainage overhang at the location where the adjacent turns overlap thereby permitting a lower edge of the turn of the fiber bed collecting media strip to drain liquid from the turn. 
     
     
       55. A fiber bed assembly as set forth in  claim 54  wherein the projecting portion of the intermediate drainage layer generally underlies the overhang. 
     
     
       56. A fiber bed assembly as set forth in  claim 55  further comprising a master layer of drainage material located in generally opposed relation with the portions of the intermediate drainage layer projecting from between adjacent turns of the fiber bed collecting media strip for receiving captured liquid and soluble solids to be drained from the intermediate drainage layer between the adjacent turns. 
     
     
       57. A fiber bed collecting media strip for use in making a fiber bed for a fiber bed mist eliminator used to remove aerosols and/or wetted soluble solids from a moving gas stream, the fiber bed being adapted to generally cover a support structure of the fiber bed mist eliminator for generally blocking flow of the gas stream through the support structure except for through the fiber bed, the fiber bed collecting media strip comprising an elongate strip formed of fibers capable of removing aerosols from the moving gas stream, the strip having opposite longitudinal edges and being sized for covering the support structure by wrapping around the support structure in multiple overlapping turns, the strip having opposite, generally flat faces, at least one of the faces having an alignment marking thereon located a distance from one of the longitudinal edges of the strip for aligning the opposite longitudinal edge of an adjacent turn of the strip. 
     
     
       58. A fiber bed collecting media strip as set forth in  claim 57  wherein the alignment marking extends generally parallel to at least one of the edges. 
     
     
       59. A fiber bed collecting media strip as set forth in  claim 58  wherein the alignment marking is located nearer one of the longitudinal edges of the strip, and at least about two inches (6 cm) from the nearer longitudinal edge. 
     
     
       60. A fiber bed assembly for a fiber bed mist eliminator used to remove aerosols and/or wetted soluble solids from a moving gas stream, the fiber bed assembly comprising:
 a fiber bed support having a wall defining an upstream space and a downstream space, the wall including openings therein to permit the gas stream to move generally freely through the wall from the upstream space to the downstream space; 
 a fiber bed supported by the fiber bed support and generally covering the wall openings so that the gas stream passes through the fiber bed moving from the upstream space to the downstream space, the fiber bed comprising a composite fiber bed collecting media strip including; 
 a first layer comprising a mat of fibers constructed to provide structural integrity to the fiber bed, and 
 a collection layer supported by the first layer, the collection layer being non-needle punched, the collection layer having a higher collection efficiency than the first layer, and the first layer and collection layer being joined together along at least one of their longitudinal edge margins.